使用`while(scanner.hasNextLine())`时如何处理最后一行？

Question

As the title states, right now I have something that looks like this:

Scanner scanner = new Scanner(System.in);

while(scanner.hasNextLine()){
     string input = scanner.nextLine();
     switch(input){
          case 1:
          do stuff;
          break;

          case 2:
          do stuff;
          break;

          case 3;
          printf("we're done here");
          scanner.close();
          System.exit(1);
     }
}

Obviously, my actual code isn't this simple, but the general idea is the same. The loops work, and it'll process every line until the last. And here's the problem, it won't process the last line, the one that actually exits the program....

The answer is probably very simple, but I can't really think of it from the top of my head. How can I process the last line?

Answer 1

Try the below code it works, Use System.exit(0) should come outside switch.

Scanner scanner = new Scanner(System.in);
boolean flag = false;
while(scanner.hasNextLine()){
     string input = scanner.nextLine();
     switch(input){
          case 1:
          do stuff;
          break;

          case 2:
          do stuff;
          break;

          case 3;
          printf("we're done here");
          flag = true;
          break;
      }
      if(flag) {
         System.exit(0); //try 'break' too.
      }
      
}

Answer 2

You need to move the code for the last case statement to the outside of the while loop. The scanner won't have another line and the loop will break.